WiMAX R6 control architecture

ABSTRACT

Within an access services network (ASN) operable for providing wireless access services to an access terminal and including a base station communicatively coupled to an ASN gateway, a new functional process identified as an “R6 controller” is provided within the framework. The R6 controller includes both a controlling entity process residing and executing within the ASN gateway and an agent entity process residing and executing within the base station. The R6 controller entities monitor the R6 reference point between these two peer instances of the R6 controller, including executing a keep-alive procedure for determining the status of the R6 interface. If a problem is detected, interested client applications are notified and further actions (e.g., initiate handover process, notify ATs, etc.) may be taken. Optionally, the R6 controller entities function as gateways enabling centralized processing for message transmitted between peer instances of other client application processes spanning the base station—ASN gateway pair.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 USC 119(e) to U.S. provisionalApplication Ser. No. 60/777,637, filed on Feb. 28, 2006, and which isincorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to wireless communicationsystems, and more particularly to a method and system for establishingand maintaining a controller for an R6 reference point between an accesspoint (e.g., base station) and a gateway controller within a wirelessaccess service network.

BACKGROUND

The Worldwide Interoperability for Microwave Access Forum (WiMAX) hasdeveloped a specification that describes a radio interface for wirelessdata communications. This specification is known as the Institute ofElectrical and Electronic Engineers (IEEE) 802.16e-2005 standard, and isincorporated herein by reference. This air interface is similar toWireless Fidelity (WiFi) (also known as IEEE 802.11, including a, b andg versions) since a user device is connected wirelessly to an accesspoint. However, WiMAX provides higher capacity, allows greatercommunications distances and provides mobility (access across differentaccess points).

Users gain wireless connectivity in an access service network (ASN) viaan access point (AP). WiMAX access points (also known as base stations)are similar to cellular access points, with each base station generallyincluding a tower with antenna(s) situated that are locally controlledand include a base transceiver station (BTS) (sometimes also referred toas a base station controller). Once connected, users have the ability toroam from one access point (base station) to another access point.

Within the ASN, each BTS is connected (via wireless or wireline) to acontroller node identified as a “gateway” (GW). Each gateway isgenerally responsible for controlling and communicating with a number ofBTSs and is connected to a global network. Control and informationrelevant to a local BTS exists in the BTS. Control and informationrelevant to both the ASN of the end users and the BTSs exist in thegateway.

Within a WiMAX network, the ASN is broken down into functional pieces,for example, user security, accounting, mobility and quality of service(QoS). These functional entities reside or are located in the BTS, thegateway, or both. Thus, a functional entity may span both the BTS andgateway. For example, for accounting, an accounting agent exists on theBTS to monitor traffic locally. The agent reports statistics about auser's traffic behavior to the corresponding accounting controller onthe gateway.

The definition of the functional entities (including peer applicationsof processes) and where they are located is defined by the WiMAX NetworkWorking Group (NWG). WiMAX NWG has developed two draft documentsdescribing various definitions and standards relating to the networksystem architecture for WiMAX networks, known as the (1) WiMAXEnd-to-End Network Systems Architecture, Stage 2 (Release 1, Aug. 8,2006) and (2) WiMAX End-to-End Network Systems Architecture, Stage 3(Release 1, Aug. 8, 2006), which are incorporated herein by reference.Stage 2 describes functional entities within the network while Stage 3defines interfaces between functional entities.

Communication between each of the peer functional entities on the BTSand gateway takes place via an interface and architecture known as the“R6 reference point.” However, these documents do not fully define itsoperation and architecture. The Stage 2 and Stage 3 documents appear todefine a distributed architecture for the R6 reference point, such thateach functional entity operates independently, or almost independently,of each other. In this manner, an agent application in the BTScommunicates directly with its corresponding control application in thegateway over a simple User Datagram Protocol (UDP) port. As such, a“peer application” (or process) is generally defined as including twoportions or entities—a peer agent entity residing and executing withinthe BTS and a corresponding peer control entity residing and executingwithin the gateway, with these two entities communicating with eachother. Each agent and corresponding control application may also bereferred to by itself as a “peer application.” Each peer application orprocess utilizes both a special protocol header and yet-to-be definedstandard messages. If a set of peer applications (i.e., togetherperforming a main function in the ASN) requires either reliability orsecurity, the set is required to build a protocol to provide thisfunctionality between them. In addition, no mechanism is described orsuggested for the BTS to discover the gateway, or vice versa, or tomaintain state. For example, if a BTS is powered off or fails, thegateway has no indication of this event. Further, though keep-alivemechanisms have been suggested, this is on a per peer application basiswith each peer application performing some keep-alive procedure. Havingeach peer application perform such a procedure results in duplicationand increased overhead.

The WiMAX NWG Stage 2 or 3 documents do not provide any clear proposalrelating to these issues for the R6 reference point. Initialdescriptions therein indicate that there is no centralized applicationto assume any shared responsibilities. Rather, these responsibilitiesare distributed to each of the individual peer applications. Withrespect to reliability, due to the inclusion of different manufacturerstrying to solve a given problem, a patchwork of solutions have beenproposed. For example, some have defined an explicit acknowledgement foreach message sent, while others have suggested a response with animplied acknowledgment, all within each specific peer application. Stillothers have not implemented any reliability.

Accordingly, there are needed methods and systems that provide acontroller application for the establishment and maintenance of the R6reference point (notably the R6 interface between the BTS and gatewayASN) within a WiMAX ASN, as well for providing discoverability andheartbeat communications therebetween.

SUMMARY

In accordance with one embodiment, a method is provided for controllingor monitoring an R6 reference point within an access services network(AS) between a base station and an ASN gateway. The method includesexecuting a R6 controller agent process within the base station;transmitting a first R6 controller-specific message to a correspondingR6 controller controlling process executing within the ASN gateway;receiving a second R6 controller-specific message from the R6 controllercontrolling process; and monitoring status of the R6 reference point inresponse to the received message

In accordance with another embodiment of the present invention, there isprovided a computer program embodied on a computer readable medium andoperable to be executed by a processor within a communications device orsystem, the computer program comprising computer readable program codefor performing the method described above. In yet another embodiment, anaccess network is provided with the means for performing the stepsdescribed above.

In accordance with yet another embodiment, there is provided an accessservices network (ASN) operable for providing wireless access servicesto an access terminal. The access services network includes a remotebase station and an access services network (ASN) gatewaycommunicatively coupled to the base station. One or more clientapplication processes each provide a defined function within the ASN,with each client application process comprising a controlling entityoperable for execution within the ASN gateway and an agent entityoperable for execution within the base station, and wherein thecontrolling entity and agent entity are further operable for sending andreceiving client application-specific messages therebetween via a R6reference point. The network further includes an R6 controller operablefor monitoring the R6 reference point between the base station and theASN gateway. The R6 controller includes a controlling entity operablefor executing within the ASN gateway and an agent entity operable forexecuting within the base station. Both the R6 controller controllingentity and R6 controller agent entity are operable for sending andreceiving R6 controller-specific messages therebetween via the R6reference point.

Other technical features may be readily apparent to one skilled in theart from the following figures, descriptions, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawings, wherein likenumbers designate like objects, and in which:

FIG. 1 depicts in block diagram form a wireless communications networkin accordance with the present invention;

FIG. 2 is an ASN reference model illustrating the various referencepoints between functional devices associated with the ASN;

FIG. 3 illustrates current architecture including a plurality of peerapplications executing in one or more BTS in accordance with the WiMAXNWG description (Stage 2, Stage 3);

FIG. 4 illustrates a BTS-ASN gateway architecture in accordance with thepresent disclosure;

FIG. 5 illustrates a process or message flow between the BTS and the ASNgateway; and

FIG. 6 illustrates message/data flow between an R6 controller peer andthree client application peer instances for a BS instance executingwithin a BTS.

DETAILED DESCRIPTION

FIG. 1 illustrates an example communications network architecture orsystem 100 in accordance with the present invention. The system ornetwork 100 shown in FIG. 1 is for illustration purposes only. Otherembodiments of the system 100 may be used without departing from thescope of this disclosure. Reference to “standards” in the following textis meant to encompass existing and future versions of the referencedstandards, as well as standards encompassing the principles of theinvention disclosed and claimed herein.

In this example, the system 100 includes an access services network(ASN) 102, a data network 104, and one or more access terminals 106. TheASN 102 includes one or more base stations (identified as a “BTS”) 110communicating with one or more ASN gateways 112 via a data network 114.In one embodiment, the system 100 (or portions thereof) is a wirelesscommunications network compliant or operating in accordance with theIEEE 802.16e standard (WiMAX). Though only one ASN 102 is shown, thesystem 100 may include additional ASNs 102.

It will be understood that the system 100 may also be configured toinclude various devices and networks such as connectivity servernetworks (CSN), not shown, or be designed with different configurations.The ASN gateway 112 provides a gateway function between the BTSs 110 andthe data network 104 (and the CSNs). Each BTS 110 generally includes oneor more antennas and various hardware and software components. Inaddition, each BTS 110 includes one or more BS “instances” (BS) 120 witheach BS instance 120 representing a sector, with the BTS 110 controllingthe BS instances within a BTS 110. For example, each BTS 110 may includethree BTS instances (three sectors).

The network 104 and/or data network 114 may include one or more localarea networks (“LAN”), metropolitan area networks (“MAN”), wide areanetworks (“WAN”), all or portions of a global network, or any othercommunication system or systems at one or more locations, or combinationof these, including the public switched telephone network (PSTN),Internet, packet networks and the like. In one specific embodiment, thenetwork 104 is an Internet Protocol (IP) based network. Typically, thenetwork 104 is utilized for communications between the BTSs 110 and theASN gateways 112, as well as between the ASN gateways 112 and otherdevices (not shown) coupled to the network 104 and within the system100. As such, it will also be understood that the data network 114 maybe separate from, or form a part of, the data network 104.

The ASN 102 has coupled thereto one or more access terminals (AT) 106(several shown). The AT 106 is operable for communicating wirelesslywith the ASN 102 over an air interface. Additional or fewer BTSs 110 andASN gateways 112 may be included in the ASN 102 (or the system 100),with the ATs 106 communicating with one or more BTSs 110 over wirelessinterfaces. Different configurations of system 100 may be utilized inaccordance with the present disclosure.

The ASN 102 typically includes a complete set of network functions toprovide radio access to the AT 106 (such as a WiMAX compliant AT), andincludes various network elements such as one or more BTSs 110 (and BSs120) and one or more ASN gateways 112. The ASN 102 defines a logicalboundary and represents the aggregation of functional entities andcorresponding message flows associated with access services. The BTS 110typically includes a BS 120 and corresponding antenna (not shown) forproviding access functions for the AT 106, as well as both WiMAX MAC andPHY compliance. The ASN gateway 112 includes control plane functionalentities that are paired with a corresponding functional entity in theBTS 110 (or BS 120), a resident function in a CSN (not shown), or afunction in another ASN 102 or ASN gateway 112.

It will be understood that the grouping and distribution of functions orfunctional entities of the system 100 (most notably the ASN 102)realized by one physical device or distributed over multiple physicaldevices is an implementation choice, provided the functional andinteroperability requirements are met.

The structure and functionality of the ASN, BTS, BS and ASN gateway aregenerally well-known. Each generally includes various components such asprocessing units, controllers and network interfaces, which necessarilyinclude but are not limited to, microprocessors, microcontrollers,memory devices, and/or logic circuitry, and these may be adapted toimplement various algorithms and/or protocols. No additional descriptionof the conventional functionality and application of ASN, BTS, BS, andASN gateway, other than as noted herein or relevant for an understandingof the present invention, is provided, as these are known to those ofordinary skill in the art.

A reference point is a conceptual point between two groups of functionsthat reside in different functional entities on each side of thereference point, also referred to as interfaces between the functionalentities. These are identified using the nomenclature “RX” referencepoint, and defined in the standards (e.g., R1—between AT 106 and ASN102; R3—between ASN 102 and CSN; R4—between ASN 102 and another ASN;R6—between BTS 120 and ASN gateway 112; R8—between one BS 110 andanother BS 110). This disclosure will focus on the R6 reference pointbetween the BTS 110 and the ASN gateway 112, as described more fullyherein.

It will be understood that the ASN 102, the BTS 110, the ASN gateway 112and the BS 120 may be constructed or configured from any suitablehardware, software, firmware, or combination thereof for providing thefunctionality known to those of ordinary skill in the art. These deviceswill include additional functionality as described below in accordancewith one or more embodiments.

Other components, devices or networks may be included in the system 100,and FIG. 1 only illustrates but one exemplary configuration to assist indescribing the system and operation of the present invention to thoseskilled in the art. The system represented in FIG. 1 may be describedusing different nomenclature or system terminology, such as use of theterms mobile subscriber terminals (MS or MT) (an access terminal), basetransceiver stations or base station controllers (BTS or BSC), radionetwork controllers (RNC) and mobile switching centers (MSC), radioaccess network (ASN), and the use of any given nomenclature to describea device within the system 100 is not intended to limit the scope ofthis disclosure.

The AT 106 represents a device utilized by a user or subscriber duringcommunication sessions over/within the system 100. For example, each ofthe communication devices may include an input/output device having amicrophone and speaker to capture and play audio information.Optionally, the communication device 106 may also include a cameraand/or a display to capture/display video information. During acommunication session, the AT 106 communicates with one or more otherdevices coupled/connected to the network 104 (or within the system 100).In this way, the AT 106 may exchange audio, video, graphical, or otherinformation during a communication session.

The AT 106 may be constructed or configured from any suitable hardware,software, firmware, or combination thereof for transmitting or receivinginformation over a network. As an example, the AT 106 could represent atelephone, videophone, computer, personal digital assistant, and thelike, etc.

The BTS 110 (or BS instance 120) and ASN gateway 112 define the R6reference point therebetween and are interconnected via one or morecommunications lines are usually wired (but may be wireless), or anycombination thereof, through the data network 114. System 100 (and datanetworks 104 and 114) may utilize any suitable protocol or protocols,and in a specific embodiment, the communications link (wireless orwireline) between the BTS 110 and the ASN gateway 112 functions inaccordance with the Internet Protocol, and in a specific embodiment, inaccordance with IPv4 or IPv6.

The R6 reference point includes a set of control (non-bearer) and data(bearer) plane protocols for communication between the BTS 110 and theASN gateway 112. Generally speaking, the bearer plane (R6e) includes theuser data path, while the control plane (R6d) includes protocols foruser datapath establishment, modification, and release control inaccordance with the AT 106 mobility events. The R6d plane is the“decision point” of the R6 reference point, while the R6e plane is the“enforcement” point.” Typically, a data path is established between theBTS 110 and the ASN gateway 112 using one or more data path tunnelsbetween two endpoints (using IP addresses), such as GRE, MPLS or VLAN orother tunneling or data path protocol. Each data path tunnel may beprovisioned with one or more sub-channels on a per AT 106 basis, per BSinstance 120 basis, and/or per data type basis (e.g., VOIP)). Thecontrol path is typically established between the BTS 110 and the ASNgateway 112 using UDP over IP, in accordance with the WiMAX Stage 2/3specifications. This may be accomplished using IP addresses between twopoints and/or UDP ports for BS instances 120 on the BTS 110. In oneembodiment, the BTS 110 has one IP address and utilizes UDP ports todistinguish among BS instances 120 therein. As described below, clientpeer application instances (among each BS instance) are distinguishablebased on message type in the Stage 3 messaging format specification. Inanother embodiment, each BS 120 may have a different IP address andutilization of UDP ports for distinguishing among BSs 120 may not benecessary.

Now referring to FIG. 2, there is shown the ASN 102 reference modelillustrating the various reference points between functional devicesassociated with the ASN 102. It will be understood that the BTS 110 mayinclude more than one BS 120.

Now referring to FIG. 3, there is illustrated the current architectureincluding a plurality of peer applications 200-208 executing in one ormore BTSs 120 (within one or more BSs 110) in accordance with the WiMAXNWG description (Stage 2, Stage 3). It will be understood that each BTS110 may operate with any number of BS instances, however, in one examplethere may be three instances—one for each sector (though each BS 110 mayhave its own BTS 120).

During normal operation, peer applications or processes areactivated/executed in response to access requests (or upon startup of aBTS or BS) from an AT or during an established communication sessioninvolving an AT 106. Each peer application or process is a functionalentity comprising two portions—one portion executing within the ASNgateway 112 and another portion executing within the BTS 120. Examplesof peer applications or peer processes include a radio resource (RR)process 200, a handover (HO) process 202, a quality of service (QoS)process 204, a paging process 206, and an extensible authentication(EAP) process 208. Generally, one instance of the controlling entity foreach process (200 a, 202 a, 204 a, 206 a, 208 a) resides and executeswithin the ASN gateway 112 and controls and communications with acorresponding agent entity for each process (200 b, 202 b, 204 b, 206 b,208 b) within each BTS 120. Other peer applications or processes may bepresent, including those currently provided in the WiMAX standard, andperhaps others, including as a data path process, an R3 mobilityprocess, an accounting process, a security process, and a contextdelivery process. Those shown are for illustrative purposes only.

Though not shown in the diagram, the number of peer applicationinstances 200 b-2008 b for each peer application 200-208 will generallyequal the number of BS instances 120 within the BTS 110 (e.g., one agentpeer entity for each BS 120). For example, with three BSs instances 120there will be three instances of each peer agent application executingor activated in the BTS 120.

Currently, each the controlling (20Xa) and agent (20Xb) entities of thefunctional units 200-208 communicate with each other via the R6reference point using UDP over IP. In other words, the NWG standarddescribes the R6 reference point as a simple UDP connection (via datanetwork 114) between peers. The Stage 3 messaging format is utilized(using a UDP control header) which includes a message type fieldidentifying the process 200-208 to which the message belongs. Eachprocess 200-208 generally operates independently of the others and isinitiated and executed in response to an access request (and accessconnection) relating to an AT 106. Since there are multiple BTSs 110associated with a single ASN gateway 112, and there may be multiple BSs120 in each BTS 110, this translates to potentially hundreds of BSs 120each having an agent entity process operating therein and associatedwith the controlling entity process within the ASN gateway 112.

With each process 200-208 handling its own unique and specific function,some or all may provide reliability, security, maintenance, and/orcommunications management capabilities for within its own realm (i.e.,for itself). Thus, if any of these peers provide any such capabilities,it is limited to those capabilities specifically related to thatparticular process, thereby necessitating each process to perform thefunctions, which results in processing duplication and additionaloverhead.

The present disclosure provides for a new architecture for the BTS110—ASN gateway 112 pair relating to the R6 reference point. A newfunctional entity is provided and identified as the “R6 controller” peerapplication or process. The R6 controller process will include twoportions, similar to the other processes 200-208, with a controllingentity residing and executing at the ASN gateway 112 and an agent entityresiding and executing at each BTS 120. The R6 controller processprovides the following functionality: R6 peer discovery via a discoverymechanism, capabilities or configuration exchange between BS peers, andR6 peer relationship maintenance via a global or centralized keep-alivemechanism or procedure.

The R6 controller process may also provide gateway and formattingfunctions for the known processes 200-208, referred to as “client peerapplications.” Formatting and transmission of standards compliantmessages will be the responsibility of the R6 controller process ratherthan each of the peer applications processes 200-208. In addition, theR6 controller beneficially institutes a keep-alive mechanism orprocedure globally (on a BTS per ASN gateway basis) to replace theindividual keep-alive mechanisms that may be running in each client peerapplication. Thus, reliability and security can be supplied by the R6controller process.

As described below, introduction and implementation of the R6 controllerprocess within the architectural framework will allow for thecentralization of responsibilities which are shared, at present, by manyclient functional entities. The R6 controller process takesresponsibilities which are common to many functional entities and ratherthan distribute this responsibility, centralizes them into onefunctional entity known as the R6 controller. As described, examples ofshared responsibilities are reliability, security, peer capabilities andconfiguration exchange, peer discovery and peer state maintenance.

Consolidation of the R6 interface to a single functional entity providesseveral advantages. It is simpler, easier to implement, limits costs dueto typical standards modifications churn and centralizes standardscompliance. Distributing this functionality to thedesigners/manufacturers of the present functional entities wouldincrease time, cost and complexity of these entities. The presentdisclosure allows for less expensive and easier integration with otherstandard-compliant products.

Now referring to FIG. 4, there is illustrated a new BTS-ASN gatewayarchitecture including the plurality of peer application processes200-208 executing in the one or more BSs 110 (within one or more BTSs110) and the ASN gateway 112. A new peer application process 210,identified as the R6 controller process 210, is introduced. Generally, asingle instance (or possibly multiple instances) of a controlling entity210 a resides and executes within the ASN gateway 112 and controls andcommunicates with one or more corresponding agent entities 210 b withineach BTS 120. Generally, multiple instances (e.g. one per BS 120) of anagent entity 210 b resides and executes within the BTS 110 and controlsand communicates with the corresponding agent entity 210 a within theASN gateway 112. The R6 controller 210 is therefore, another majorprotocol functional entity within the ASN 102.

In one embodiment, the R6 controller 210 (and each of its entities) isembodied as a software process that executes within the respectivegateway 112 and BTS 110 as a software process component of the overallhardware/software system configuration for these devices. However, theR6 controller 210 and its entities may also be constructed of one ormore discrete hardware/software components that interoperate with theother components of the gateway 112 and/or BTS 110.

The present disclosure further provides for a set of messages (ormessaging protocol) between the R6 controller agent entity 210 a and thecorresponding R6 controller entity 210 b within the ANS gateway 112.These messages are compliant with the R6 messaging protocol, such as theWiMAX Stage 3 messaging format. The messages are transmitted via the R6interface. Various location independent messages (i.e., originating fromeither R6 controller entity) may be generated and transmitted by the R6controller 210. These may include R6 controller hello, acknowledgement,configuration, and keep-alive messages. Other messages/types may beutilized as desired. In one embodiment, the messaging structure andformat for the R6 controller 200 complies with the WiMAX standards (NWG)(see, Stage 3 Messaging Format), with a unique function type identifyingthe R6 controller and various message types, such as described above.

Now referring to FIG. 5, there is shown one embodiment of a process ormessage flow between the BTS 110 and the ASN gateway 112. Upon power-up,restart or initial connection or operational start of a BTS 110 or ASNgateway 112 in the ASN 102, one or both of the R6 controller agents 210a, 210 b initiates a process to discover its corresponding R6 controlleragent. This is accomplished through utilization of R6 hello andacknowledgment messages.

A HELLO message is generated and transmitted from the R6 controllerentity 210 b after the client agent entities 200 b-208 b associated withthe BTS 110 are operational. Generally, this occurs when at least one BSinstance 120 (and its associated peer agents) are up and running. The R6controller entity 210 b may determine this operational status using oneof various methods, including polling the agents directly, checking acentral status register or registers (updated by the agents) orreceiving specific messages from the agents. Similarly, the R6controller controlling entity 210 a may generate HELLO messages (notshown in FIG. 5).

In one embodiment, the R6 controller agent 210 b corresponds to the BTS110. FIG. 5 and the description herein describe a configuration in whicha single R6 controller agent 210 b is associated with the BTS 110.However, in another embodiment, multiple R6 controller agents 210 bmight be provisioned within the BTS 110 with each corresponding to a BSinstance 120 (which may also include an additional BTS-specific R6controller agent), and all or some of the teachings and processesdescribed herein may implemented in each such instance of the R6controller agent 210 b.

As shown in FIG. 5, the BTS 110 transmits an R6 HELLO message to the ASNgateway 112 (step 500). The ASN gateway 112 responds with an ACK(acknowledgement) message (step 502). ACK messages may be automatic ormay be generated when all client controller entities are determined tobe executing or active within the ASN gateway 112. This processeffectively enables the R6 controller entities 210 a, 210 b to discovereach other, and as a result, the BTS 110 and ASN gateway 112 initiallydiscover each other.

In addition to the HELLO and ACK message handshake originated by the BTS110, or alternatively, a similar R6 HELLO and ACK message handshake(shown in dotted lines) may be originate from the ASN gateway 112.

A CONFIG message carrying configuration or capabilities information mayalso be utilized and managed by the R6 controller 210. A CONFIG messageoriginated by the BTS 110 includes base station information (e.g., BSid, neighboring BS ids, paging info., etc.) and is transmitted to theASN gateway 112 (step 504). An ACK message may be transmitted inresponse (step 506). Similarly, and either independently or in responseto the BS CONFIG message (504), the ASN gateway 112 transmits an ASNgateway configuration message which includes gateway and other systeminformation (e.g., keep-alive interval, dead interval, UDP ports forsession managers, paging controllers etc.) to the BS 120 (step 508). AnACK message may be transmitted in response (step 510). It will beunderstood that the CONFIG messages from the BTS 110 are generallyper-BTS, but when each BS instance 120 becomes operational, a new CONFIGmessage may be sent with its corresponding information.

To monitor operational status of the R6 reference point or interface,the R6 controller performs and manages a keep-alive procedure orprocess. KEEP ALIVE messages and corresponding ACK messages are alsoutilized thereby enabling the R6 controller entities 210 a, 210 b todetect a problem with the R6 connection point or interface. Thus, the R6controller 210 utilizes and manages a single or centralized keep-aliveprocess on behalf of all the client applications 200-208. As a result,none of the client applications need to perform their own keep-aliveprocess, thus eliminating duplicity and decreasing overhead controltraffic over the R6 interface. As with HELLO messages, the KEEP ALIVEprocess and its messages are usually executed by the single R6controller agent 210 b, but if multiple R6 controller agents exist (oneper BS instance, and perhaps one associated with the overall BTS 110),the process may be implemented by each such R6 controller agent 210 b.

In most embodiments, the client applications 200-208 (and each of theirentities) do not individually transmit any KEEP ALIVE messages orexecute any keep alive process or procedure. This is done centrally bythe R6 controller 210.

As shown in FIG. 5, a KEEP ALIVE message is generated and transmitted tothe ASN gateway 112 (step 512). An ACK message may be transmitted inresponse (step 514). Thereafter, periodic KEEP ALIVE messages aretransmitted, and corresponding ACK messages are received, by the BTS110. The KEEP ALIVE messages (512) are usually transmitted in accordancewith the keep-alive interval. The keep-alive interval is set by the ANSgateway 112 (and usually carried in a CONFIG message) but may bedetermined by the BTS 110. Optionally, when an ACK message is notreceived, a secondary dead interval period may be used during which theBTS 110 tries again to send one or more additional KEEP ALIVE messages.

When an expected ACK message is not received in response to transmissionof a KEEP ALIVE message, the R6 controller agent 210 b concludes thereis a problem with the R6 interface, and takes appropriate action. Suchaction may include, but is not limited, to informing one or more of thelocal client applications 200 b-200 b of the problem (passive or activecommunication, such as by setting status bits in a register, sendingindividual messages, etc.), having the session manager inform all ATs106 of this issue, initiate hand-off procedures for the ATs 106, or anyother function(s) as desired.

It will be understood that the ASN gateway 112 may also originate andsend KEEP ALIVE messages for redundancy purposes.

The HELLO, CONFIG, KEEP ALIVE and ACK messages will generally includetransaction identification (TID) and sequence numbers (S), and may alsocarry additional information. As will be appreciated, all or some of theforegoing messages may be combined into one message that includes theinformation in the multiple messages.

As noted, the same or similar process may be implemented for each BSinstance 120, instead of, or in addition to, implementation by the R6controller agent 210 b associated to the BTS 110.

In another embodiment, the R6 controller entities 210 a, 210 b functionas gateways (e.g., collection, dissemination, modification, and/orformatting) for the R6 messaging information transferred between activeagent and controlling client application process pairs 200 a-200 b, 202a-202 b, 204 a-204 b, 206 a-206 b, 208 a-208 b.

Now referring to FIG. 6, there is illustrated message/data flow betweenthe R6 controller peer 210 b and three of the client application peerinstances 202 b (HO), 204 b (QoS), and 208 b (EAP) executing within aBTS 120. Each peer instance includes a corresponding message queue 302b, 304 b, 308 b, 310 b. For illustrative purposes, only three clientapplication peer processes are shown. In general, client applications200 b-208 b generate and send peer-intended messages (messageinformation) to the R6 controller 210 b. The R6 controller 210 bconverts the messages into a standards format message (e.g., an R6message compliant with WiMAX standards) and transmits these to itscorresponding R6 controller 210 a via the data network 114. Though notshown in FIG. 5, client applications 200 a-208 a similarly generate andsend peer-intended messages (message information) to the R6 controller210 a in the ASN gateway 112. The R6 controller 210 a converts themessages into a standards format message (e.g., an R6 message compliantwith WiMAX standards) and transmits these to its corresponding R6controller 210 b via the data network 114.

Upon receipt, the receiving R6 controller 210 a, 210 b translates orconverts the received R6 message into another format and relays themessage (or the relevant messaging information) to the destination peerclient application 200-208.

In one embodiment, each of the R6 controller entities 210 a, 210 b andthe client application entities 200 a-208 b includes a message queue(with transmission and reception queues). If desired, the transmissionof messages in the transmission portion of the queue 310 a, 310 b of theR6 controllers may be prioritized. For example, messages to/from the HOclient application 202 a, 202 b (or the R3 mobility client application,not shown) may have priority over messages from other clientapplications due to increased importance.

In addition, the R6 controller gateway messaging scheme enablesdetection of problems with a client peer application or the R6controller peer (and even problems with a BTS 110 or ASN gateway 112)and provides notification to interested client applications 200-208.Thus, when a problem is detected by the R6 controller 200, a problemnotification message is generated and sent to each of the clientapplications 200-208 for notification purposes. Depending on the type ofproblem, the client applications agents 200-208 will take further actionconsistent with the type of problem notified to them.

The R6 controller 210 may provide other functions, such as reliablemessage transport and secure message transport. This may applied to themessage exchange for the R6 controller messages, as well as the R6messages exchanges between client application pairs 200-208 controlledand monitored by the R6 controller 210.

In one embodiment, the processes and system described herein operate inaccordance with the WiMAX standard(s) (802.16e-2005, NWG Stage 2, 3).However, the concepts and teachings herein may be utilized with otherprotocols or specifications.

In some embodiments, some or all of the functions or processes of theone or more of the devices are implemented or supported by a computerprogram that is formed from computer readable program code and that isembodied in a computer readable medium. The phrase “computer readableprogram code” includes any type of computer code, including source code,object code, and executable code. The phrase “computer readable medium”includes any type of medium capable of being accessed by a computer,such as read only memory (ROM), random access memory (RAM), a hard diskdrive, a compact disc (CD), a digital video disc (DVD), or any othertype of memory.

It may be advantageous to set forth definitions of certain words andphrases used throughout this patent document. The terms “include” and“comprise,” as well as derivatives thereof, mean inclusion withoutlimitation. The term “or” is inclusive, meaning and/or. The phrases“associated with” and “associated therewith,” as well as derivativesthereof, mean to include, be included within, interconnect with,contain, be contained within, connect to or with, couple to or with, becommunicable with, cooperate with, interleave, juxtapose, be proximateto, be bound to or with, have, have a property of, or the like.

While this disclosure has described certain embodiments and generallyassociated methods, alterations and permutations of these embodimentsand methods will be apparent to those skilled in the art. Accordingly,the above description of example embodiments does not define orconstrain this disclosure. Other changes, substitutions, and alterationsare also possible without departing from the spirit and scope of thisdisclosure, as defined by the following claims.

1. An access services network (ASN) configured for providing wirelessaccess services to an access terminal, the access services networkcomprising: a remote base station; an access services network (ASN)gateway communicatively coupled to the base station; one or more clientapplication processes each providing a defined function within the ASN,each client application process comprising a controlling entityconfigured for execution within the ASN gateway and an agent entityconfigured for execution within the base station, and wherein thecontrolling entity and agent entity are further configured for sendingand receiving client application-specific messages therebetween via a R6reference point; an R6 controller configured for monitoring the R6reference point between the base station and the ASN gateway, the R6controller comprising a controlling entity configured for executingwithin the ASN gateway and an agent entity configured for executingwithin the base station, the R6 controller controlling entity and R6controller agent entity being further configured for sending andreceiving R6 controller-specific messages therebetween via the R6reference point.
 2. The network in accordance with claim 1 wherein theone or more client application processes comprises a one of: quality ofservice (QoS), handover (HO), data path, context delivery, R3 mobility,radio resource manager (RR), paging and security.
 3. The network inaccordance with claim 1 wherein the R6 controller-specific messagestransmitted over the R6 reference point are in accordance with a WiMAXNWG Stage 3 formatting standard.
 4. The network in accordance with claim1 wherein the R6 controller-specific messages transmitted over the R6reference point comprise a keep-alive message transmitted at apredetermined time.
 5. The network in accordance with claim 4 whereinthe keep-alive message is transmitted in response to expiration of akeep-alive timer.
 6. The network in accordance with claim 4 wherein thekeep alive message is generated and transmitted by the R6 controlleragent entity executing within the base station, and wherein the R6controller agent entity performs one or more actions in response to afailure to receive a corresponding acknowledgment message from the R6controller agent entity executing within the ASN gateway.
 7. The networkin accordance with claim 1 wherein the R6 controller further providesmanagement and control functions for the R6 reference point.
 8. Thenetwork in accordance with claim 1 wherein each of the one or moreclient application agent entities sends the client application-specificmessages in a first format to the R6 controller agent entity within thebase station, and the R6 controller agent entity sends these messages ina second format to its corresponding R6 controller controlling entitywithin the ASN gateway.
 9. The network in accordance with claim 8wherein the second format is WiMAX NWG Stage 3 standard compliant.
 10. Amethod for controlling an R6 reference point within an access servicesnetwork (AS) between a base station and an ASN gateway, the methodcomprising: executing a R6 controller agent process within the basestation; transmitting a first R6 controller-specific message to acorresponding R6 controller controlling process executing within the ASNgateway; receiving a second R6 controller-specific message from the R6controller controlling process; monitoring status of the R6 referencepoint in response to the received message; executing a plurality ofclient application agent processes within the base station; generatingin a first format a first plurality of client application-specificmessages intended to be received by a plurality of corresponding clientapplication controlling processes executing within the ASN gateway;sending the plurality of client application-specific messages to the R6controller agent process; generating, by the R6 controller agentprocess, a second plurality of client application-specific messages in asecond format from the first plurality of client application-specificmessages; and transmitting the second plurality of clientapplication-specific messages to the ASN gateway.
 11. The method inaccordance with claim 10 further comprising: executing the R6 controllercontrolling process within the ASN gateway.
 12. The method in accordancewith claim 10 wherein the first message in formatted in accordance witha WiMAX NWG Stage 3 standard.
 13. The method in accordance with claim 10wherein the first message comprises a keep-alive message and the secondmessage comprises an acknowledgment message; and wherein theacknowledgement message corresponds to the first message.
 14. The methodin accordance with claim 13 further comprising: transmitting thekeep-alive message after a predetermined time period has elapsed. 15.The method in accordance with claim 14 further comprising: resetting akeep-alive timer with a keep-alive interval in response to receiving thesecond message.
 16. The method in accordance with claim 15 furthercomprising: initiating one or more actions within the base station inresponse to failing to receive the acknowledgment message.
 17. Themethod in accordance with claim 10 wherein the second format is WiMAXNWG Stage 3 standard compliant format.
 18. A computer program embodiedon a non-transitory computer readable medium and operable to be executedby a processor within a base station, the computer program comprisingcomputer readable program code for: executing a R6 controller agentprocess within the base station; transmitting a first R6controller-specific message to a corresponding R6 controller controllingprocess executing within the ASN gateway; receiving a second R6controller-specific message from the R6 controller controlling process;monitoring status of an R6 reference point between the base station andthe ASN gateway; executing a plurality of client application agentprocesses within the base station; generating in a first format a firstplurality of client application-specific messages intended to bereceived by a plurality of corresponding client application controllingprocesses executing within the ASN gateway; sending the plurality ofclient application-specific messages to the R6 controller agent process;generating, by the R6 controller agent process, a second plurality ofclient application-specific messages in a second format from the firstplurality of client application-specific messages; and transmitting thesecond plurality of client application-specific messages to the ASNgateway.
 19. The computer program in accordance with claim 18 whereinthe first message is a keep-alive message and the second message is acorresponding acknowledgment message, and the computer code is furtheroperable for: transmitting the keep-alive message after a predeterminedtime period has elapsed; resetting a keep-alive timer with a keep-aliveinterval in response to receiving the corresponding acknowledgmentmessage; and initiating one or more actions within the base station inresponse to failing to receive the acknowledgment message.
 20. Thecomputer program in accordance with claim 18 wherein the first messagecomprises a keep-alive message and the second message comprises anacknowledgment message; and wherein the acknowledgement messagecorresponds to the first message.